Electronic devices are often made up of many modules that are put together in such a way that they accomplish the task for which the overall electronic device is designed. Proper function of the device often requires extensive communication between and among the modules that make up the device. In many devices, the communication between modules is done using electrical signals. Electrical communication, however, hits bandwidth limits as the communication speed increases. Optical communication has emerged as an attractive alternative to electrical communication because it does not suffer the same bandwidth problems that electrical communication suffers.
Despite its advantages, however, optical communication between components in a device comes with its own set of challenges. Part of the advantage of a modular device design is that the individual modules are easy to install and can be easily removed from the device for either replacement or upgrade. Where modules that communicate optically are involved, one challenge brought on by the modular design is how to “connectorize” the individual modules, giving each module one or more separable interfaces so that they can easily be inserted and connected to the device and removed from the device when necessary.
One current approach is to pre-fabricate an already connectorized waveguide and mount it on the top surface of the package substrate. The pre-fabricated connectorized waveguide has a rigid connector attached to the end of a flexible waveguide. Attaching an already connectorized waveguide to a module requires accurate positioning on the module (usually on a substrate that is part of the module) of a component which includes both a rigid connector and flexible waveguide. This presents significant manufacturing difficulties, principally because machines used to manufacture the modules can usually only handle rigid components or flexible components, but not components that include both rigid and flexible parts. While in some cases existing machines can be made to handle components that include both rigid and flexible parts, this adds significantly to the cost of manufacturing the module and significantly affects the accuracy (i.e., the dimensional tolerances) with which the connector can be attached to the module.